Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has a wide range of applications and uses. PTFE is also commonly known as Teflon. PTFE is a high-molecular-weight compound that includes carbon and fluorine atoms. PTFE is heat resistant, ductile, and hydrophobic (i.e., lacks polar groups and therefore is insoluble in water and does not have water absorption properties). The high strength of carbon-fluorine bonds makes PTFE generally very unreactive, and hence PTFE is often used for manufacturing containers and pipework for reactive and/or corrosive chemicals. In addition, the high electronegativity of the fluorine atoms of PTFE causes PTFE to demonstrate mitigated London dispersion forces, and accordingly PTFE possesses a low (e.g., significantly low) coefficient of friction against any other solid. Therefore, PTFE is useful as a lubricant for reducing friction, wear, and energy consumption of machinery (or machine components).
There are many existing methods and techniques for preparing homogenous mixtures of synthetic polymeric resins with a wide variety of solid phase additives. For example U.S. Pat. No. 4,649,168 (Kress et al) discloses the dispersion of PTFE particles in aromatic polycarbonate resin based molding compositions. The dispersion is carried our by admixture of aqueous emulsion PTFE and aromatic polycarbonate resin followed by coagulation of the emulsion-mixture. However, while the process of U.S. Pat. No. 4,649,168 results in fine dispersions of PTFE in polycarbonate resin, the degree of dispersion is generally dependent upon a number of variables, each variable requiring close control. Therefore, there exist limitations in workability of PTFE compositions, as well as products manufactured from such PTFE compositions, associated with U.S. Pat. No. 4,649,168.
In addition, European patent document EP-A-0,166,187 describes a powder composition containing PTFE. The powder of EP-A-0,166,187 is obtained by mixing a dispersion of PTFE with a latex of grafted PTFE, filtering and drying in order to obtain a powder. However, existing powders obtained by co-precipitation (also known as co-coagulation or co-flocculation powders) tend to display high self-adhesion tendencies, particularly when the powders have a high PTFE content (e.g., 25% or more by weight). Accordingly, these powders generally cannot flow freely, thereby making such powders difficult to handle, work, and/or store.
There are several different existing methods, processes, and techniques for preparing or producing PTFE-based or containing compositions (e.g., powders), additives, and products. However, there exist a variety of drawbacks, disadvantages, and/or limitations with these existing methods and techniques. Specifically, many existing methods for preparing PTFE-based or containing compositions, additives, or products are often complicated and/or costly. Furthermore, existing PTFE-based or containing compositions, powders, and additives are generally associated with difficulties and/or limitations in relation to workability and/or storage.